Over the decades, the average American's head size has increased. In the 1960's it was 7 1/8. Now it has probably surpassed 7 1/4 and is headed for 7 3/8. Manufacturers are aware of this long term trend, but until the 2005 model year they apparently doubted that there is a large enough market for extra large helmets to make a profit on them.

The one exception to this reluctance was Bell Sports Inc. In response to requests from us to many manufacturers over a period of years, and inspired by inquiries from consumers who could not find a large enough helmet, Bell began in September, 1997 to market its Kinghead model, a unique helmet that meets the CPSC bicycle helmet standard and is sized to fit up to size 8 1/4 heads (26 inches/66cm circumference). It uses standard foam pads inside for fitting. It is still the largest bicycle helmet available. We have been informed by people with 66cm heads that it actually fits them.

Bell sold very few Kingheads and never actively marketed the helmet. You can still order one at your local bicycle shop. If you are in an area with no local bicycle shop, call Bell at (800) 456-BELL. We have also found them on the Web at the company now marketing motorcycle helmets with the Bell name. (We believe that Bell Sports has now bought them back.) Some with big heads are avoiding the Kinghead because they find the design clunky. (We like that rounder-smoother shape for safety.)

Unfortunately Bell dealers online are now using the Kinghead designation for the Triton model, calling it the Kinghead Triton. The Triton is a different helmet, and only fits up to 65cm heads. We can only assume that listing it that way is another nasty marketing trick.

In 2005, your choices expanded. Vigor introduced a helmet called the Duo that they advertise as fitting 26.0 inch/66 cm. heads, equal to the Kinghead. In 2007 they added the Vigor Royal, again a 26 inch helmet. Several other brands now have a helmet for heads of 25.6 inch/65cm, 25.2 inch/64cm or 24.8 inch/63cm:

• Bell Kinghead: fits up to 26.0"/66cm heads. NOT "Kinghead Triton"
• Vigor Duo: fits up to 26.0"/66cm heads.
• Vigor Royal: skate style, fits up to 26.0"/66cm heads.
• Bell Triton: fits up to 25.6"/65cm heads. (aka "Kinghead Triton")
• Cratoni Radon: fits up to 25.6/65cm heads. (rounder interior)
• Specialized Air Force: fits up to 25.6/65cm heads.
• LAS Big Devil: fits up to 25.2"/64cm heads.
• Met Testagrossa: fits up to 25.2"/64cm heads.
• Etto Vortex: fits up to 25.2"/64cm heads.
• Giro Atlas II: fits up to 24.8"/63cm heads.
• Limar Big One: fits up to 24.8"/63cm heads.
• Louis Garneau Rev and Robota: fit up to 24.8"/63cm heads, but some emailers tell us that Garneau's larger sizes fit them better than others.
• Netti Quantum Pro: fits up to 24.8"/63cm heads.
• Specialized Aurora (discontinued for 2008): fits wider heads than most size large helmets.
• Trek Interval XL: Fits up to 26.0"/66cm heads

You can find comments on each of these helmets in our Helmets for the Current Season article.

Many tape measures are not accurate. Measuring your head is not very precise, either, so the numbers above should not be taken as exact.

Success in fitting a large head depends on the shape as well as the size. Some emailers report that they can use a smaller size with some helmets due to the shape, or that one helmet with the same measurements has more room for them than another. That depends on the individual head shape and the interior profile used by the manufacturer, both difficult for us to pin down and best determined by a fitting. We do note that the Cratoni Radon seems to work better for rounder heads. We have more on that on our page about helmets for rounder heads. That can also mean more room for a wider head.

You may have already tried one of these helmets, and of course you have already tried removing most or all of the foam fitting pads. That is the only way to make more room for your head without modifying the helmet in a way that reduces protection.

If demand becomes more evident, more large helmets will appear on the market. We have tried to help by giving helmet manufacturers at ASTM helmet standards committee meetings copies of letters from consumers who were searching desperately for larger helmets, and suggesting to the manufacturers that there might be money to be made making a larger helmet.

Please let us know with an email if you find other good solutions to this problem that we can pass on to the next person with a very large head, or if you find a helmet that works particularly well with your head shape.

This page was last revised on: January 15, 2008.

Email us about your experience with big helmets.